In the fields of cosmetic products, drugs, quasi drugs, food products and the like, applications of hydrogel particles in which a large number of disperse phase portions containing an oil component are dispersed in a continuous phase portion of non-crosslinked hydrogel have been studied.
Patent Document 1 describes, as the hydrogel particles, ones in which the oil component contains a solid oil and/or a liquid oil.
Patent Document 2 describes, as the hydrogel particles, ones in which the disperse phase portions are liquid phase containing the oil component, and zinc oxide particles and titanium oxide particles, which have a UV-shielding property, are dispersed in the disperse phase portions.
Patent Document 3 describes, as the hydrogel particles, ones in which the disperse phase portions are solid phase containing the oil component, and zinc oxide particles, which have a UV-shielding property, are dispersed in the disperse phase portions. According to the hydrogel particles, the disperse phase portions in which the zinc oxide particles are dispersed are solid phase, and therefore, the zinc oxide particles are immobilized and are stably present in the disperse phase portions. Therefore, for example, when the hydrogel particles are applied to a cosmetic product or the like, it is possible to avoid a problem that zinc oxide particles leak out of the hydrogel particles and react with other ingredients.